Patchwork block: fix cache flushing in bdrv_commit

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Submitter Christoph Hellwig
Date Jan. 17, 2010, 11:32 a.m.
Message ID <20100117113230.GB18966@lst.de>
Download mbox | patch
Permalink /patch/43022/
State New
Headers show

Comments

Christoph Hellwig - Jan. 17, 2010, 11:32 a.m.
On Thu, Jan 14, 2010 at 11:21:15AM +0100, Kevin Wolf wrote:
> Anthony, you seem to have missed the v2 patch that considered my review
> comments. Can you please apply the diff between v1 and v2 on top?

Here is the differences in patch form:

---
From: Christoph Hellwig <hch@lst.de>
Subject: block: fix cache flushing in bdrv_commit

As pointed out by Kevin Wolf the previous patch returned early if we
there is a bdrv_make_empty method and it missed a cache flush for the
frontend device after the bdev_make_empty call.  This patch fixes it
up.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Anthony Liguori - Jan. 20, 2010, 2:58 p.m.
On 01/17/2010 05:32 AM, Christoph Hellwig wrote:
> On Thu, Jan 14, 2010 at 11:21:15AM +0100, Kevin Wolf wrote:
>    
>> Anthony, you seem to have missed the v2 patch that considered my review
>> comments. Can you please apply the diff between v1 and v2 on top?
>>      
> Here is the differences in patch form:
>
> ---
> From: Christoph Hellwig<hch@lst.de>
> Subject: block: fix cache flushing in bdrv_commit
>
> As pointed out by Kevin Wolf the previous patch returned early if we
> there is a bdrv_make_empty method and it missed a cache flush for the
> frontend device after the bdev_make_empty call.  This patch fixes it
> up.
>
> Signed-off-by: Christoph Hellwig<hch@lst.de>
>    

Applied.  Thanks.

Regards,

Anthony Liguori
> Index: qemu/block.c
> ===================================================================
> --- qemu.orig/block.c	2010-01-17 12:27:03.589006970 +0100
> +++ qemu/block.c	2010-01-17 12:27:55.718008519 +0100
> @@ -589,6 +589,7 @@ int bdrv_commit(BlockDriverState *bs)
>       BlockDriver *drv = bs->drv;
>       int64_t i, total_sectors;
>       int n, j;
> +    int ret = 0;
>       unsigned char sector[512];
>
>       if (!drv)
> @@ -620,8 +621,10 @@ int bdrv_commit(BlockDriverState *bs)
>           }
>       }
>
> -    if (drv->bdrv_make_empty)
> -	return drv->bdrv_make_empty(bs);
> +    if (drv->bdrv_make_empty) {
> +        ret = drv->bdrv_make_empty(bs);
> +        bdrv_flush(bs);
> +    }
>
>       /*
>        * Make sure all data we wrote to the backing device is actually
> @@ -629,7 +632,7 @@ int bdrv_commit(BlockDriverState *bs)
>        */
>       if (bs->backing_hd)
>           bdrv_flush(bs->backing_hd);
> -    return 0;
> +    return ret;
>   }
>
>   /*
>
>
>
>

Patch

Index: qemu/block.c
===================================================================
--- qemu.orig/block.c	2010-01-17 12:27:03.589006970 +0100
+++ qemu/block.c	2010-01-17 12:27:55.718008519 +0100
@@ -589,6 +589,7 @@  int bdrv_commit(BlockDriverState *bs)
     BlockDriver *drv = bs->drv;
     int64_t i, total_sectors;
     int n, j;
+    int ret = 0;
     unsigned char sector[512];
 
     if (!drv)
@@ -620,8 +621,10 @@  int bdrv_commit(BlockDriverState *bs)
         }
     }
 
-    if (drv->bdrv_make_empty)
-	return drv->bdrv_make_empty(bs);
+    if (drv->bdrv_make_empty) {
+        ret = drv->bdrv_make_empty(bs);
+        bdrv_flush(bs);
+    }
 
     /*
      * Make sure all data we wrote to the backing device is actually
@@ -629,7 +632,7 @@  int bdrv_commit(BlockDriverState *bs)
      */
     if (bs->backing_hd)
         bdrv_flush(bs->backing_hd);
-    return 0;
+    return ret;
 }
 
 /*